Locks for securing axles to a differential

ABSTRACT

The axle lock is formed by a cam plug and a set of balls mounted within an axially disposed recess at the inner end of the axles which are supported in driving relation within the side gears of the differential. The rotation of the pinion gear shaft moves the cam plugs further into the recesses and the balls outwardly into locking engagement within an annular recess within the side gears. The pinion gear shaft is then secured against rotation by a pin or screw which extends therethrough.

mted States Patent 1 51,713 Mueller [4 1 Mar. 28, 1972 [54] LOCKS FORSECURING AXLES TO A 2,187,843 1/1940 Rzeppa ..74/71a DIFFERENTIAL I3,310,999 3/1967 Griffith ..74/7l0 [72] Inventor: Otto Mueller, 13Byfield Lane, Dearborn, primary c. Husar M1611. 48120 Anameyl-larness,Dickey & Pierce [22] Filed: May 1, 1970 ABSTRACT Appl 33843 The axlelock is formed by a cam plug and a set of balls mounted within anaxially disposed recess at the inner end of 52] us. CL ..74 713 h ax s hh are upp rt in dri ing relation within the 5 m (3 1 1, 1 40 side gearsof the differential. The rotation of the pinion gear [58] Field ofSearch... ..74/710, 713 shaft moves the cam Plugs further into therecesses and the balls outwardly into locking engagement within anannular [56] References Cited recess within the side gears. The piniongear shaft is then secured against rotation by a pin or screw whichextends UNITED STATES PATENTS gh- 1,508,832 9/1924 Zimmerschied et a1...74/713 10 Claims,8Drawing Figures 1'1 9 1/ 1 1 j I! 11 Hi i? 1/ 7 Z/i; r f/ 27 :14 ff Ma 1/ 1 17 ff L 1 1/ ill {1,1 {7

PAlENTEnmRzs I972 SHEET 1 OF 3 PATENTEBMAR28 I972 3.651.713

SHEET 3 OF 3 a. MMHE IN z; m I /wzwrmt I f #5 )h/lw LOCKS FOR SECURINGAXLES TO A DIFFERENTIAL BACKGROUND OF THE INVENTION Reference may be hadto the O; Mueller Patent No. 3,393,583, issued July 23, 1968 forSelf-Locking Differential Transmission."

SUMMARY OF THE INVENTION The present invention pertains to a simplifiedlock for securing the inner ends of the axles of a vehicle to the drivenelements of a differential and retain said axles in driving position. Ithas been the practice to lock the axles in driving position within thedifferential near the outer ends of the axles or secure the inner endsagainst outward movement during the assembly of the case within thedifferential housing. With the present lock, the axles can be secured tothe side gears after the assembly of the case within the housing by therotation of the pinion shaft after the axles have been inserted in theside gears. This is especially desirable when the case is constructed asa unit element which produces a locking differential while being driven.The inner ends of the axles are recessed for receiving a cam plug whichis movable axially therein. The wall formed by the recess has one ormore apertures through which locking detents are projectable.

In the embodiment herein illustrated, camming recesses are provided inthe plug and apertures extend through the wall of the recess which areeventually spaced substantially 120 apart in alignment with the cammingrecesses. A ball is retained in each aperture by a slight peaning of theouter wall surface about the aperture edge. When the balls are inretracted position, the cam plugs extend beyond the outer end of theaxle recesses in position to extend within notches on opposite sides ofthe pinion shaft when the balls are aligned with an annular recess inthe wall of the aperture through the side gears. Upon turning the pinionshaft 90, the cam plugs are moved further into the recesses and theballs are cammed outwardly into the annular recess in the side gears andthereby lock the axles against axial movement. The pinion shaft isthereafter locked against rotation by a pin, screw or other element.

BRIEF DESCRIPTION OF THE DRAWINGS a present invention;

FIG. 2 is a broken sectional view of structure illustrated in FIG. 1,taken on the line 2-2 thereof;

FIG. 3 is a reduced view of structure, similar to that illustrated inFIG. 1, showing another form of the invention with the axles locked inposition;

FIG. 4 is a sectional view of the structure illustrated in FIG. 3, takenon the line 4-4 thereof;

FIG. 5 is a view of the structure illustrated in FIG. 3, taken at thecentral portion thereof showing the inserted axles with the lockingelements in retracted position;

FIG. 6 is a view of structure similar to that illustrated in FIG. 3,showing another form of the invention with the axles locked to the sidegears;

FIG. 7 is a sectional view of the structure illustrated in FIG. 6, takenon the line 77 thereof, and

FIG. 8 is a view of the structure illustrated in FIG. 6 before the axlesare locked to the side gears.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2, adifferential is illustrated having a housing 10 which supports a case 11on a pair of like bearings 12. The case supports a ring gear 14 which isdriven by a pinion 15 through a stub shaft 16 secured to the housing 10by one or more bearings 18 and driven through a transmission and engine(not shown) in the conventional manner. The case 11 supports a set ofpinion gears 21 having teeth which mate with teeth of side gears 22which are of conventional construction. The pinion gears 21 aresupported on a shaft 24 which extend through apertures in the case 11and which is locked in position against turning by a pin 25 havingthreads on one end thereof. The side gear 22 have internal splines 26engaged by splines 27 on the inner ends of the driven axles 28.

Each axle 28 has a recess 29 on the inner end in which a cam plug 31 ismounted for axial movement. The cam plug 31 has three equally spacedtruncated spherical recesses 32 therein which when the cam plug extendsoutwardly beyond the end of the shaft support detents in the nature ofhardened balls 33 within apertures 34 through the wall outwardly portionof the axle defining the recess. The recesses 32 in the cam plugs 31have a sloping portion 35 which cams the balls 33 outwardly when thecam' plugs 31 are moved into the recesses 29 for moving the ballsoutwardly of the apertures 34 further into an annular recess 36 ofarcuate cross section. The recess 36 cuts through the splines in theaperture 37 of the side gears and when the balls extend therein to theaxles are retained against longitudinal movement. The balls are retainedwithin the apertures 34 by having the outer ends thereof peaned inwardlyat one or more points 38 for preventing the balls from falling from theapertures but which permits them to extend outwardly thereof.

When the axles are inserted into the case and side gears, the balls aremoved inwardly and cam the cam plugs 31 outwardly into extended positionso as to enter the notches 30 in opposite faces of the pinion gear shaft24. The shaft 24 is turned by a tool inserted in a receiving recess 41provided in the end of the shaft. This rotation moves the cam plugs 31away from each other toward the bottom of the recesses 29 camming theballs 33 outwardly into the annular recesses 36 in the side gears. Theshaft 2 4 is retained in the 90 rotated position by the pin 25 which islocked in position by the threaded end 42 and lock washer 43.

If either or both of the shafts are to be removed, it is only necessaryto remove the screw 42 with its pin 25 and rotate the shaft 24 to alignthe cam plugs with the notches 39 in the shaft 24 to permit the balls 33to cam the plugs 31 forwardly as the axles 28 are withdrawn to permitthe balls to leave the annular recess 36 in the side gears 22 and movewithin the aperture 34 in the wall portion of the axles to permit theaxle or axles to be withdrawn.

The locking of the axles in this manner to the side gears is ofimportance when the locking differential illustrated and described inthe above set forth patent and illustrated herein in FIGS. 3, 4 and 5 isemployed in the housing assembly. With the case 47 of unit constructionand with the differential gearing 48 assembled therein along with thefluid actuated torque bias control unit 49, the particular lock for theaxles has specific application. In this arrangement, a closed hydraulicloop circuit controls the torque bias between the pair of axles. An axle51 not only is driven by a side gear 52 but the axle also drives a camelement 53 by which the pistons 54 of the torque bias control unit 49are driven. The operation of the control unit 49 is clearly illustratedand described in the above men tioned patent and will not be furtherdescribed herein. A second axle 55 is connected to a side gear 56 in themanner pointed out hereinabove. The locking of the axles 51 and 55 tothe side gears 52 and 56 of the differential unit occurs upon therotation of the pinion shaft 57. The shaft is prevented from turningthereafter by a pin 58 retained in position by a threaded section 59thereon having an O-ring for sealing the pin aperture. The shaft has apinion 63 at each end and flats 64 thereon for permitting a flow of oilbetween the surface of the aperture of the pinions and that of the shaft57. A pinion shaft support 60 has an aperture 61 through which the shaft57 extends and an aperture 62 into which the inner ends of the sidegears 52 and 56 extend. The shaft 57 is sealed to the case 47 and to thesupport 60 by O-rings 71. The side gears 52 and 56 The structure ofFIGS. 6, 7 and 8 is similar to that of FIGS. 3, 4 and 5 with theexception that instead of using a pinion 65 on each end of the pinionshaft 66, two additional pinions 67 are employed which are mounted onstub shafts 68 and 69 disposed in aligned relation and 90 from the shaft66. The stub shafts 68 aresealed to the case by O-rings 71 and to apinion shaft support 72 through which the shaft 66 extends. The support72 has aligned apertures 73 into which a shouldered end of the stubshafts 68 and 69 extend and in which they are sealed by O-rings 74. Thepinion shaft 66 is likewise sealed to the case 50 and to the pinionshaft support 72 by similar O-rings 71. The side gear 52 is sealed tothe pinion shaft support 72 by an O-ring 80 and to the torque biascontrol unit 49 by an O-ring 81. The side gear 56 is sealed to thepinion shaft support 72 by an O-ring 80 and to the case by an O-ring 81.All of the pinion gears and side gears are sealed within the case andfrom the splined area of the side gears and the axle ends which extendwithin the case. The interior of the case forms a reservoir for oilwhich is in communication with the torque control unit 49 through thepassageway 70.

After the pinion shaft 66 has been rotated through 90 to move the camplugs 31 into locking position, as illustrated in FIGS. 6 and 7, a screw75 is passed through an aperture in the stub shaft 69, through anaperture 76 at the center of the shaft 66 and into a threaded aperture77 at the inner end of the stub shaft 68. This not only locks the stubshafts into fixed aligned relation to each other and the sleeve 72 butalso prevents the shaft 66 from turning. With this arrangement, fourpinions are employed for driving the two side gears, as illustrated inFIGS. 6. 7 and 8, instead of a single pair of pinions, as illustrated inFIGS. 3, 4 and 5.

The axles are illustrated as having locking elements at the inner endwhich may be applied to a standard differential or to locking or othertypes of differentials which are completely assembled before the axlesare applied thereto. This permits the inner ends of the axles to belocked to the driving members of the differential after the completeassembly thereof. The axles and the locking elements are hereinillustrated as being the same in all instances, the cam plug means orsimilar locking elements being moved into the recesses at the end of theaxles by the rotation of the pinion shaft through 90 to engage therecesses in the side gears and lock the axles against longitudinalmovement. The pinion shaft is thereafter prevented from rotating by theuse of a threaded pin extending therethrough and through the case or bythe use of a screw for joining the two stub shafts to the pinion shaftwhen four pinions are employed in the differential unit.

JIJO

lclaim:

1. In a differential housing, a case within said housing having drivingmeans, pinion gears carried by said case for driving a pair of said sidegears which drives a pair of aligned axles, the inner end of each axlehaving a recess extending thereinto, a shaft for supporting said piniongears having cam means between the ends thereof, axles extending withinthe side gears, movable means within the recess at the inner ends ofeach axle engageable by said cam means, and means for rotating saidshaft and cam means which moves said movable means into lockingengagement with said side gears.

2. In a differential as recited in claim 1, wherein said movable meansis a cam plug within a recess in the adjacent axle ends, and meansextensible through the wall of the recess into recess means within theside gears when the cam plugs are moved into the recesses in the axlesby said cam means.

3. In a differential as recited in claim 2, wherein the cam means on theshaft are notches on opposite sides thereof.

4. In a differential as recited in claim 3, wherein said extensiblemeans are balls which move within apertures in the axle wall.

5. In a differential as recited in claim 4, wherein said recess means inthe side gears is a groove into which said balls extend when locking theaxles to the side gears against longitudinal movement.

6. In a differential as recited in claim 5, wherein engaging splines areprovided on the exterior surface of the shaft ends and within the sidegears for providing driving relation therebetween. I

7. In a differential as recited in claim 1, wherein a second pairofpinions are employed, stub shafts for said last pinions, a supportabout the pinion shaft having aligned apertures into which the innerends of the stub shafts extend, and a screw extending through one of thestub shafts and said pinion shaft into a threaded aperture in said otherstub shaft.

8. In a differential as recited in claim 1, wherein securing means isprovided for preventing the rotation of the pinion shaft after it isactuated.

9. in a differential as recited in claim 8, wherein said securing meansis a screw having a pin extending from one end thereof.

10. In a differential as recited in claim 7, wherein the pinion gearsshaft, stub shafts and side gears are sealed to the pinion shaft supportand to the case to retain a lubricant therewithin.

1. In a differential housing, a case within said housing having drivingmeans, pinion gears caRried by said case for driving a pair of said sidegears which drives a pair of aligned axles, the inner end of each axlehaving a recess extending thereinto, a shaft for supporting said piniongears having cam means between the ends thereof, axles extending withinsaid side gears, movable means within the recess at the inner ends ofeach axle engageable by said cam means, and means for rotating saidshaft and cam means which moves said movable means into lockingengagement with said side gears.
 2. In a differential as recited inclaim 1, wherein said movable means is a cam plug within a recess in theadjacent axle ends, and means extensible through the wall of the recessinto recess means within the side gears when the cam plugs are movedinto the recesses in the axles by said cam means.
 3. In a differentialas recited in claim 2, wherein the cam means on the shaft are notches onopposite sides thereof.
 4. In a differential as recited in claim 3,wherein said extensible means are balls which move within apertures inthe axle wall.
 5. In a differential as recited in claim 4, wherein saidrecess means in the side gears is a groove into which said balls extendwhen locking the axles to the side gears against longitudinal movement.6. In a differential as recited in claim 5, wherein engaging splines areprovided on the exterior surface of the shaft ends and within the sidegears for providing driving relation therebetween.
 7. In a differentialas recited in claim 1, wherein a second pair of pinions are employed,stub shafts for said last pinions, a support about the pinion shafthaving aligned apertures into which the inner ends of the stub shaftsextend, and a screw extending through one of the stub shafts and saidpinion shaft into a threaded aperture in said other stub shaft.
 8. In adifferential as recited in claim 1, wherein securing means is providedfor preventing the rotation of the pinion shaft after it is actuated. 9.In a differential as recited in claim 8, wherein said securing means isa screw having a pin extending from one end thereof.
 10. In adifferential as recited in claim 7, wherein the pinion gears shaft, stubshafts and side gears are sealed to the pinion shaft support and to thecase to retain a lubricant therewithin.